Dual wheel and brake construction



May 6, 1941-. v. G. GARNETT ETAL DUAL WHEEL AND BRAKE-CONSTRUCTION Filed Dec. 23, 1938 m www N5 E WNW .NMA GG GV. M D 0g l .A 0 T w 3 C D W5 3 llllllu MTORNEY.

Patented Mey s, 1941 DUAL WHEEL Ann BRAKE ooNsTaUcTioN Vactor G. Garnett and Edward Denver, Colo.

V. Garnett,

Application December 23, 1938, Serial No. 247,378

7 Claims.

This invention relates to a dual wheel mounting and to a. dual wheel brake structure for heavy motor vehicles such as trucks, busses, etc.

'I'he principal object of this invention is .to provide a wheel mounting, more particularly a front wheel mounting, for dual wheels in which all bendin tlains, uneven wheelloadings, etc. encountered in the usual dual wheel cantilever axles are eliminated.

Another object of' the invention is to establish a pivot between each pair of dual front wheels so that lthe Vload and the forward thrust will -be equally distributed between the two Wheels and so that very little effort will be required for turning and guiding the Wheels.

A still further object is to provide a cushioning spring arrangement for .the wheels of a type which will permit mounting between dual wheels and which will support the Vehicle on a light spring when traveling with a light load or empty and upon increasingly heavier springs as the load thereon increases.

A still further object is to provide a braking arrangement for du-al wheels which, when the brakes are applied, will not exert a turning action on the front wheel pivots but in which the retarding action on one wheel will be counteracted by the retarding action on the other wheel of each pair so that there will be no twisting or bending strain imposed upon the tie rod or other par-ts of the steering mechanism.

A still further object is to provide a dual front wheel mounting and brake structure whichwill inherently follow the road and eliminate all necessity for lthe usual camber, caster and toe-in of the wheels and in which all uneven tire wear is eliminated.

Other objects and advantages reside in *the detail construction of .the invention, which is designed for simplicity, economy, and eiliciency. These will 'become more apparent from the following description.

In the' following detailed description of the invention reference is had to the accompanying f Adrawing which forms a part hereof. Like numerals refer to like parts in all views of the drawng and throughout .the description.

In the drawing:

Fig. 1 is a front view of a typical truck struc ure with the invention applied thereto.

f" Fig. 2 is a vertical section taken on the `line 2, Fig. 1. y

r Fig. 3 is an enlarged section taken on the line "3-3, Fig. 2.

Fig. 4 is a horizontal section through the wheel (Cl. 28o-96.2)

:pivot member looking downwardly on 'the dual wheels.

The chassis or weight carrying portion of the truck isindicated in the drawing at I0. 'Illis invention contemplates placing a transverse beam II across the chassisl I0 which projects beyond 'both sides thereof.` The beam may have any desired cross section. A cylindrical tube, as illustrated, has been found very satisfactory.

Vertical A:tubes I2 extend downwardly from ad- .j'acent each extremity of the lbeam I I. A plunger post I3 is vertically slidable in each of the tubes I2 and projects downwardly below the lower extremity thereof. 'I 'he plungers terminate in axle members I4, from which, wheel axles I5 oppositely project.

Each ofthe wheel axles I5 supports one wheel of a pair of dual wheels I6 upon suitable wheel bearings Il. The wheels IB are, of course, .providedwiththe usual .tires I8. The axles I5 are in axial alignment with each other and are of equal length so Ithat the wheels I6 are equally spaced from and parallel with the plunger I3.

An outer spring cup I9 is secured to the beam II immediately above each of .the tubes I2, the latter' passing completely through the lbeam II. The weight on the beam II is transmitted .to the plunger i3 vthrough a plurality of springs of dii'- ieren-t strength. In the embodiment illustrated tniee springs are employed, a light spring 2u, an intermediate spring 2| and a heavy spring 22.

'ine llgnt spring/Zu is 'compressed between a rotary thrust bearing member zo, on the upper extremity or' the ,plunger` lll, and the bottom of an inner, hanged, inverted spring cup 24. The intermediate spring ZI is compressed between me ilange on the cup 24 and Ithe bottom of an inverted, flanged, intermediate spring cup 2o. 'i'.he intermediate spring cup 25 is sirmlar .to ithe inner spring cup except i'or size and the heavy spring z2 is compressed :between its peripheral nange, shown at Z6, andthe closed bottom of the nxed inverted spring cup I9. The latter is welded or otherwise secured to the beam I I.

It can be readily seen that if .the truck is empty or lightly loaded, only fthe light spring 20 will function. If this load increases, the spring 20 will be compressed until a point is reached when its :increasing reaction will begin to compress .the mtermediate Spring. If the load is still further increased, the reaction of the intermediate spring will .be transmitted to the heavier spring 22. Therefore, the spring strength of the chassis' I0 is directly proportional 'to the load thereon downwardly over the sleeve 21 in telescopic engagement therewith. It can be readilyv seen that the plunger Il is completely sealed against the entrance o! any foreign matter and all abrasion will occur in the sleeves 21 and 2l and not in the plunger.

While the above described wheel suspension is more particularly designed and more particularly valuable for use on the iront wheels of vehicles, wherein the plunger I3 can act as the turning pivot, it can alsobe'applied to the rear wheels by fixing the plunger against rotation. For front wheel use, each of the axle members wheels oi the dual pairs simultaneously and with equal pressure so the reactance on both sides of each plunger is balanced.

While a specliic form of the improvement has or; an axle member secured on the lower extremity or each plunger; wheel axles extendingY oppositely outward from each of said axle members; a wheel, mounted on each of said wheel axles: an inverted ilxed spring cup secured to said beam over the upper extremity or each of Il carries a steering arm 2l which extends for- 'Y wardlytherefrom. 'I'he two steering arms are f connected together by means of the usual steering tie rod 3l.` The turning movements or the vsteering gear are transmitted through a suitable steering rod 3l. The steering gear itself may be of any .of the usual types.

' It can` be readily seen that the road drag on the tires I8 is equal on both sides of the plunger4 I3 so that the reactive forces on the two wheels counteract each other. Therefore no strains are y transmitted Vto the steering arms 29 'or the tie rod 3l and as the wheels have no' tendency to swerve in either direction, no caster, camber, or

` toe-in is necessary in the wheel axles, and they can be turned for steering purposes with a minimum of eilort.

Front wheelbraking on trucks has heretofore presented a dimcult problem due to the fact that the steering pivots of each of the wheels do not coincide with the center lines of the wheels. When the brakes are applied, an excessive rearward bending moment is imposed on the iront wheel axles and hpon the connected steering mechanism resulting in frequent break downs.

In order to minimize these bad features intricate adjustments of caster, camber, and toe-in are resorted to.

All or this has been avoided in the present construction by placing a brake upon each member oi the pair of dual wheels. one at each side of the steering pivot so that the retardingaction of one wheel is completely counteracted or counterbalanced by the reaction or the other wheel ,and the forward inertia is absorbed between the `two so that even in the most abrupt stop. there is no tendency toward horizontal rotation and no strains are placed upon the steering apparatus;

hence no caster, camber or toe-in are neces- In the embodiment illustrated, a brake drum 3l is positioned within each of the wheels i6 and secured thereto. A brake disc 33 is secured stationary tubes I2. A hydraulic conduit leads said tubes; and resilient means compressed be- .ity or each plunger; wheel axles extending oppositely outward from each of said axle members; a wheel mounted on each of said wheel axles: an inverted iixed spring cup secured to said beam over the upper extremity oi.' each oi said tubes; an inverted, inner spring cup within each o! said ilxed spring cups; a peripheral ilange projecting from each of said inner spring cups; a ilrst spring compressed between 'each oi said plungers and the bottom of its inner cup; and spring means compressed between said inner cups and said ilxed spring cups.

3. A dual` wheel mounting for a vehicle chassis comprising: a transverse beam extending across said chassis; a ilxed tube extending downwardly from adjacent each extremity or said beam; a plunger extending upwardly within each tube and projecting below the lower extremity thererromeach T-iitting to 'a central pressure line 39.

a This arrangement applies the brake shoes of all or an axle member secured on the lower extremity of `each plunger; wheel axles extending oppositely outward from each of said axle members; a. wheel mounted on each oi said wheel axles; an inverted ilxed spring cup secured to said beam over the upper extremity of each of said tubes; an inverted, inner spring cup within each of said ilxed spring cups; a peripheral flange projecting from each or said inner spring cups; an intermediate inverted ilanged spring cup surrounding and spaced'irom said inner cup; a t spring 'compressed between said inner cup and said plunger; a second spring compressed between said inner cup and said intermediate cup; and a third spring compressed between'said intermediate cup and said xed cup.

and projecting below the lower extremity thereof; an axle member ilxedly secured on the lower extremity of each plunger; wheel axles extending' oppositely outward from each of said-axle members at xed angles to the axis. of said plunger; a wheel mounted on each of said wheel axles; spring means positioned above said beam for resisting downward movement of said tubes on said plunger; resilient means for transmitting the thrust of said plunger to said spring means; and means for rotating said plunger to steer said vehicle.

5. A dual wheel mounting for a vehicle chassis comprising: a transverse beam extending across said chassis; a fixed tube extending downwardly from adjacent each extremity of said beam; a-

said chassis; axed tube extending through and downwardly from adjacent each extremity of said beam; a plunger extending upwardly within each tube and projecting below the lower extremity thereoffan axle member secured on the lower extremity of each plunger; wheel axles extending oppositely outward from each of said axle members; a wheel mounted on each of said wheel axles; spring retaining means secured to said beam over the upper extremity of each of said tubes; springs supported by said retaining means over said beam; and resilient means for transmitting the thrustof said plunger through said Ilxed tube to said springs.V Y

7. A dual wheel mounting for a vehicle chassis comprising: a transverse beam extending across said chassis; a xed tube extending downwardly from adjacent each extremity oi' said beam; a plunger extending upwardly within each tube land projecting below the lower extremity thereof; an axle member secured on the lower extremity 'o1' each plunger; wheel axles extending oppositely outward `from each axle member; a wheel mounted on each wheel axle; means for positioning a spring on said beam over the upper extremity of each of said tubes and resilient means compressed between the positioning means and said plungers to cushion the latter.

EDWARD V. GARNETI. VACTOR G. GARNE'IT. 

